1. Field of the Invention
The present invention relates to hyperpolarization methods, systems and compositions of hyperpolarizable materials suitable for various applications. Particularly, the present invention is directed to hyperpolarization methods, systems and compositions that facilitate magnetic resonance imaging (“MRI”) and nuclear magnetic resonance (“NMR”) analysis.
2. Description of Related Art
A variety of techniques are known in the art for providing hyperpolarization. Many of these techniques are directed to providing hyperpolarized noble gases. The use of a hyperpolarized noble gas, for example, can be advantageous in performing MRI or NMR as it can dramatically increase the signal to noise ratio (“SNR”) in MRI or NMR procedures. This permits MRI and NMR to be used to analyze regions of interest in unprecedented ways.
To date the emphasis in the literature has been on providing complex and expensive systems for hyperpolarization. While these systems have been generally satisfactory for the purpose for which they were intended, such systems still do not solve numerous problems in the art. For example, use of these systems has generally been limited to only those facilities and researchers that can afford such expensive and complex systems, which typically cost hundreds of thousands of dollars, or more.
Similarly, some efforts have been made at providing hyperpolarized materials to transfer hyperpolarization to targets of interest. To date these efforts have focused on hyperpolarized xenon as a solvent for NMR analysis applications. For example, in Navon, G., Song, Y.-Q., Rõõm, T., Appelt, S., Taylor, R. E. and Pines, A., (1996). Science 271, 1848, the disclosure of which is incorporated by reference in its entirety herein, hyperpolarized xenon gas was liquefied and used as a solvent; transfer of polarization to several dissolved species was demonstrated. In a similar work, Polarization Transfer using Hyperpolarized Supercritical Xenon,” Jason C. Leawoods, Brian T. Saam, and Mark S. Conradi, Chem. Phys. Lett. 327, 359-364 (2000), supercritical xenon ((P>5.83 MPa, T>290 K) was employed as a solvent and transfer of polarization to several solutes was achieved.
However, xenon is very unsatisfactory as a solvent as highly specialized physical conditions are necessary for most materials of interest to dissolve in it. These conditions are not ones that lend themselves to the great bulk of actual NMR/MRI studies. There is therefore a need in the art for a method that can provide hyperpolarized materials suitable for use at standard conditions.
In U.S. Pat. No. 6,466,814, a method of producing a hyperpolarized solution is described wherein a high T1 agent is first polarized and then dissolved in a solvent. This method has the drawback that the polarization is limited by the T1 of the agent. There is therefore a significant need in the art for new methods of manufacturing hyperpolarized solutions.
There is a also significant need in the art for hyperpolarization systems, methods and compositions that reduce the cost of obtaining hyperpolarized material, and increase the practicality of using hyperpolarized material to enhance MRI and NMR. The present invention provides solutions for these and other problems, as described herein.